The present invention relates to concrete raising, more particularly to a method and apparatus for raising concrete members and maintaining same in the new position by the use of a mud or grout, and more particularly to a portable mud pump for introducing the mud or grout into a cavity under the raised concrete member.
Generally when concrete or cement members such as flat slabs, sidewalk sections, driveways, patios, steps, and curb and gutter sections sink due to a settling of soil thereunder, etc., the sections of concrete are removed and new concrete poured, which is time consuming, costly and additionally requires the disposal of the removed concrete sections.
The present invention provides a solution to the problem of sunken concrete members and involves raising the members whereby such need not be removed and replaced. In the case of sunken concrete members, the member is lifted to its original position, or slightly higher, and a mud or grout is pumped into the cavity beneath the raised concrete member which functions to retain the member in its raised position. The mud pump produces sufficient pressure that in some instances the pumped mud will raise the concrete member.
Mud or slurry pumps are well known, as exemplified by U.S. Pat. No. 4,718,826 issued Jan. 12, 1988, No. 3,326,135 issued Jun. 20, 1967, No. 3,507,347 issued Apr. 21, 1970, and No. 4,500,267 issued Feb. 19, 1985. These prior mud pumps are either large units (not readily portable) or are small, manually operated, low volume units. The mud pump of the present invention is readily portable, small enough to fit in a corner of a pickup truck, delivers a sufficient pressure and flow rate of mud, and is easily cleaned and maintained. The portable mud pump of this invention basically consists of an air cylinder, pump body and reversing valve assembly. The remaining apparatus for carrying out the method of the present invention includes conventional concrete drills, lifting jacks, lifting members, chains and couplers. Utilizing the method and apparatus of the present invention, concrete or cement members can be repositioned to their original position in less time and at less cost than by removal and replacement.